1. Field of the Invention
This invention pertains generally to the tracking of three-dimensional rotation, and more particularly to a real-time, non-contacting, three-dimensional, angular velocity sensor used in combination with a body rotating about a point which is fixed relative to the sensor.
2. Description of Related Art
In the literature, there are a variety of devices based on a sphere rotating in a cradle. These include: spherical motors, spherical continuously variable transmissions, and omnidirectional vehicles based on the ball wheel mechanism. All of these devices require velocity feedback and would benefit from a non-contacting sensor that can track three-dimensional rotation. However, there is little work on spherical encoders or other means of three-dimensional, orientation feedback without mechanical coupling. In fact, there is no work that addresses three-dimensional, angular velocity feedback of a continuously rotating sphere without a prior knowledge of the rotation axis orientation.